1. Field of the Invention
The present invention relates to a drawing device, drawing method, and a storage medium, which properly execute a scaling down process of an image datum.
2. Description of Related Art
When outputting high-resolution image data at low resolution, a scaling down process is needed to adjust the image data to the low resolution. As an art for this process, Japanese Unexamined Patent Application, First Publication No. H07-110867 discloses a drawing device which saves a pattern of ruled lines and adjustment information for scaling for every kind of ruled lines, and outputs adjusted image data based on the saved information. In addition, Japanese Unexamined Patent Application, First Publication No. 2001-16443 discloses a device which determines data to be drawn as a character, line, and bitmap and outputs the data, converting each coordinate in accordance with an ordered scale.
The art disclosed in Japanese Unexamined Patent Application, First Publication No. H07-110867 can only be applied to preset kinds of ruled line. In the art disclosed in Japanese Unexamined Patent Application, First Publication No. 2001-16443, a portion of the data is omitted when scaling down. Detailed information concerning the data may be lost in the process, and this leads to a phenomenon whereby a drawn data lacks some ruled lines. An explanation of this phenomenon is described hereinafter.
FIG. 3 shows a part of an output result by a drawing device such as a printer and a display. An area drawn by the drawing device has a coordinate system consisting of “x” and “y”. An upper left point is set as an origin whose coordinate is x=0, y=0. Coordinate “x” increases rightward, and coordinate “y” increases downward. A minimum area specified by “x” and “y” corresponds to a point used by printers, or a pixel used by displays. FIG. 3 shows a part of an output result by the drawing device whose coordinate is 1≦x≦10, 98≦y≦102. Numbers on the left show coordinate “y”. A shaded area indicates that area being blacked out.
When a command to black out an area of 100≦y<101 is expressed as (B=100, T=101), an output result of the command is as FIG. 3 shows. When scaling down the image to 40% to output to a low-resolution drawing device, the coordinates in the command are reduced to 40%. As a result, the command is converted to (B=40, T=40.4), and then rounded to a whole number, (B=40, T=40). Since no number meets an expression 40≦y<40, no areas are blacked out, and rule lines are not drawn as shown in FIG. 4.